As the population ages in the United States, it is predicted that there will be more than 15 million Alzheimer's disease (AD) patients by 2050 and it will cost billions of dollars to take care of them Unlike other disorders, there are no simple, non-invasive or minimally invasive, sensitive, specific assays for diagnosing AD and identifying individuals who are at an increased risk for AD, like the blood PSA test for prostate cancer and the blood cholesterol test for atherosclerotic diseases.
Alzheimer's disease is a leading cause of dementia in the elderly, affecting 5-10% of the population over the age of 65 years (A Guide to Understanding Alzheimer's Disease and Related Disorders, Jorm, ed., New York University Press, New York, 1987). In Alzheimer's disease, the parts of the brain essential for cognitive processes such as memory, attention, language, and reasoning degenerate, robbing victims of much that makes us human, including independence. In some forms of Alzheimer's disease, onset can first be seen in middle age, but more commonly, symptoms appear from the 65 and onwards. Alzheimer's disease today affects 4-5 million Americans, with slightly more than half of these people receiving care at home, while the others are in many different health care institutions. The prevalence of Alzheimer's disease and other dementias doubles every 5 years beyond the age of 65, and recent studies indicate that nearly 50% of all people age 85 and older have symptoms of Alzheimer's disease (1999 Progress Report on Alzheimer's Disease, National Institute on Aging/National Institute of Health). 13% (33 million people) of the total population of the United States are age 65 and older, and this percentage will climb to 20% by the year 2025 (1999 Progress Report on Alzheimer's Disease).
Alzheimer's disease also puts a heavy economic burden on society. A recent study estimated that the cost of caring for one Alzheimer's disease patient with severe cognitive impairments at home or in a nursing home, is more than $47,000 per year (A Guide to Understanding Alzheimer's Disease and Related Disorders). For a disease that can span from 2 to 20 years, the overall cost of Alzheimer's disease to families and to society is staggering. The annual economic toll of Alzheimer's disease in the United States in terms of health care expenses and lost wages of both patients and their caregivers is estimated at $80 to $100 billion (1999 Progress Report on Alzheimer's Disease).